System of forming tunnels



Feb. 15, 1966 G. J. LEVY SYSTEM OF FORMING TUNNELS 5 Sheets-Sheet 2 G. J. LEVY SYSTEM OF FORMING TUNNELS Feb. 15, 1966 Filed May 23, 1963 Feb. l5, 1966 G. J. LEVY SYSTEM OF FORMING TNNELS 5 Sheets-Sheet 5 Filed May 25, 1965 @ff IZ.

INVENTOR ve/wldllevg ATTORNEY Feb. 15, 1966 G. J. LEVY SYSTEM OF FORMING TUNNELS 5 Sheets-Sheet 4 Filed May 23 1965 INVENTOR eald Jlleay BY @2f ATTORNEY Feb. 15, 1966 G. J. LEVY 3,234,743

SYSTEM OF FORMING TUNNELS Filed May 25, 1965 5 Sheets-Sheet 5 INVENTOR (17e/fam Le@ BY ATTORNEY United States Patent O "ice 3,234,743 SYSTEM F FORD/[ING TUNNELS Gerald J. Levy, Brooklyn, N.Y., assignor of one-half to Nathan Levine, Jackson Heights, N.Y. Filed May 23, 1963, Ser. No. 282,701 22 Claims. (Cl. 61--85) This invention relates to a system of forming underground tunnels, such as tunnels under streets, railroad tracks etc. for transportation, sewage disposal, water conveying and general conduit purposes-the invention being particularly directed to apparatus and methods for driving tunnels and conduits, of either short or relatively great lengths, through the ground.

The tunnelling method frequently employed, for most soft ground conditions and where hand-mining is not technically or economi-cally feasible, involves .the use of a shield which is moved forwardly into a previously cleared position or forced forwardly into the ground, the shield serving as an excavating aid in addition to its functions as a temporary support for overburdens and as a protective device for the miners. After each forward movement of the shield a space is left in its tail between the :tail diaphragm land the last of .the previously erected 'annular liners-part of the primary lining of the tunnel-whereby another liner can be erected in said space. Accordingly to conventional practice, jacking equipment is mounted within the center of the shield, a plurality of jacks being brought into engagement with the front annular surface of the adjacent liner (which is firmly anchored in place through its operative attachment to the preceding liner assembly), the operative force exerted by the jacks upon the stationary primary lining reacting against the rear diaphragm of the shield to move the latter forwardly. Thus, conventional shield -tunnelling techniques rall require the step of pushing the shield forwardly. It is accordingly necessary with such techniques that the primary liners be made sufficiently strong structurally not only to enable them to serve their main purpose of supporting the operative load imposed upon the tunnel, but also to enable them to withstand the tremendous stresses induced in them when temporarily serving as a reaction abutment during the process of pushing the shield forwardly into the ground. This makes it necessary to resort to costly materials and techniques, such as the use of relatively expensive cast iron liner segments, heavy gauge pressed steel segments or other fabricated steel or concrete segments with special reinforcing means, stitfened iianged liners, and such techniques as the employment of shoring-up devices, offset jacking shoes to reduce bending and moment-arm deflection of liner flanges, and relatively large-diameter jacking pistons.

It is my objective to provide an apparatus and method of tunnelling which have none yof the aforesaid shortcomings, and which eliminate the need to use liners as structural members for employment in conjunction with the shield-driving mechanisms. And in this aspect of my invention it is a further object to provide a tunnelling technique which makes possible the use of primary liners whose sole function is to support their share of the load imposed on the tunnel during use, whereby relatively light and inexpensive liners and simple erecting techniques may be employed.

In the accomplishment of the above-mentioned and other objectives of my invention, I employ therein an apparatus and method of pulling the shield forwardly into the ground, in contradistinction to the said conventional pushing method. My invention is also distinguishable from conventional apparatus and methods in that the jacking equipment for propelling the shield forwardly is mounted outside of the shield, rather than in a relatively 3,234,743 Patented Feb. 15, 1966 inaccessible and inconvenient interior portion thereof as is necessary with conventional techniques.

It is common knowledge that, despite the advantages of the use of shields for tunnel constructions, its use is often avoided because of the high cost of the primary lining, in addition to the cost of the shield itself. This is particularly true in tunnelling underneath railroad tracks, superhighways and streets, especially where the tunnel is to be used for sewage, water supply or as housing for electrical conductors or the like. The alternative methods of augering, hand-mining and pipe jacking are not always feasible due to variable ground conditions. With my invention it is possible to employ the preferable shield technique due to the economies inherent in `the pull method utilized by my apparatus.

The method of my invention also permits the accomplishment of other objectives thereof, to wit: the erection of the primary lining outside of the tunnel and the pulling of such lining into the ground when operatively attached to the shield, thereby facilitating lining erection and assembly; providing a clear path for excavated muck and dirt at the starting pit and in the shield and enabling it to be removed without interference from jacking members, as is the case with said conventional tunnelling apparatus; eliminating the tail-void-the annular space created by the differential between the outside diameter of the primary liner plate and the outside diameter of the shield-thereby obviating the conventional operation of filling in such void with pea gravel, cement grout or other materials.

Other objects, features and advantages will appear from the drawings and the description hereinafter given.

Referring to the drawings,

FIG. 1 is a vertical longitudinal section of the starting and power-supply pits flanking a section of earth through which a tunnel is to be formed by the system of my invention, the illustrated tunneling shield in the starting pit and jack device in the power-supply pit, constituting part of the apparatus of my invention, being shown in elevation, the jack device being shown in pulling position, the connecting means between the shield and jack device not being shown in this view.

FIG. 2 is a section of FIG. l taken along line 2 2.

FIG. 3 is a section of FIG. l taken along line 3--3.

FIG. 4 is a section of FIG. 1 taken along line 44.

FIG. 5 is a vertical longitudinal sectional view substantially like FIG. l, but showing the jack device in a pushing position, and showing a pipe member being pushed through the ground from the power-supply pit toward the starting pit, in accordance with a step in the method of this invention.

FIG. 6 is a View like FIG. 5 after the completion of the steps of forcing the pipe through the ground, positioning wire guide templates in the starting and powersupply pits, extending a plurality of wire tension members through the pipe while in place, and attaching the rear end portions of said wire members to the front diaphragm portion of the tunneling shield, the jack apparatus in the power-supply pit not being shown in this View.

FIG. 7 is a view like FIG. 6, but showing front portions of the wire tension members operatively attached to the carriage frame of the jack mechanism in the powersupply pit.

FIG. 8 is a view like FIG. 7, but showing the position of one of the wire strands in the process of being operatively drawn taut.

FIG. 9 is a section of FIG. 7 taken substantially along line 9 9.

FIG. l0 is a section of FIG. 8 taken substantially along line 10-10.

FIG. ll is a View like FIG. 8 after the completion of the steps of drawing all the wire strands taut.

FIG. 12 is a view like FIG. 11, but showing the tunneling shield and a number of operatively erected primary liners in position after operative pulling actions by the jack mechanism in the power-supply pit.

FIG. 13 is a view like FIG. 12, but showing the tunneling shield close to the end of its operative path through the earth, the shield being shown extending into the powersupply pit, primary liners being shown operatively in place throughout the entire extent of the tunnel.

FIG. 14 is a side elevational view of the shield member operatively employed in conjunction with my invention, fragments being sectioned for clarity.

FIG. 15 is a fragmentary front view of FIG. 14, a portion being removed for clarity.

FIG. 16 is an enlarged fragmentary vertical longitudinal section of FIG. l5, showing a plurality of liners operatively in place.

FIG. 17 is a vertical longitudinal section, substantially like FIG. 13, showing a modified form of my invention, a plurality of liners being shown operatively attached to the tunneling shield while it is being operatively drawn through the ground.

FIG. 18 is an enlarged fragmentary vertical longitudinal section of the shield and attached liners of FIG. 17.

FIG. 19 is a fragmentary longitudinal section of another form of my invention, showing a tunneling shield having an inner liner therein and rear outer liners the outside diameters of which are equal to the outside diameter of the shell of the shiel-d, this embodiment being adapted to eliminate tail void.

Referring to the form of my invention illustrated in FIGS. 1 to 16, the starting pit 20 and the power-supply pit 21, which Hank the section of earth 22 supporting the tracks 23, contain the tunneling shield 24 and the jack mechanism generally designated 25, respectively. In the embodiment shown, the shield 24 is supported by a cradle 26, FIG. 1 showing the tail 27 of the shield facing the rear of the starting pit 20 and the hood 28 in abutment with the wall of planking 29 at the front of the pit supporting the rear wall of the earth section 22. The said starting pit 20 is defined by a framework generally designated 36; and the power-supply pit 21 is dened by a framework generally designated 31. As will appear from the description hereinafter given, the shield 24 contains an internal diaphragm member 32 adapted to support tension wires `connected to the jack mechanism in the power-supply pit, the tail 27 of the shield being adapted to accommodate therein primary liners operatively erected in a manner well known to those skilled in the art. The front periphery of the hood portion 28 is adapted to pierce the earth as the shield is operatively moved forwardly, miners stationed below the hood performing their digging operations and depositing the excavated material from the earth section 22 into suitable receptacle means positioned within the shield and adapted to be withdrawn rearwardlyan operation which can be performed during the use of my invention in view of the fact that there are no obstructions withn the shield in contrast with conventional apparatus employing pushing jacks positioned centrally within the shield. It should be noted that before the start of the operation of moving the shield forwardly, the entire section 34 of the planking 29 positioned within the periphery of the outer shell of the shield is removed, thereby to permit the shield to engage the earth and perform its tunneling operation.

The jack apparatus in the power-supply pit 21 consists of carriage member 35 having a frame 36 mounted on the wheeled undercarriage 37, the latter having the wheels 38 rollably positioned on the tracks 39 supported upon the lioor of the pit. In the operative pulling position of the jack mechanism 25, such as is illustrated in FIG. 12, the rear wall 40 of the carriage frame 36 has attached thereto the pistons 41 of the hydraulic jacks 42, said jacks each having rear flanges 43 in engagement with the respective abutment members 44. In the embodiment shown, there are four hydraulic jacks 42, each being in engagement with an obliquely disposed one of said abutment members 44, the latter being operatively supported by the frame 45 in known manner. On the forward portion of the frame 36 of the carriage are a plurality of gripping devices 46, each of these being adapted to receive therethrough one of the tension wire members 81 employed in my invention (hereinbelow described) and hold them against displacement. It is not deemed necessary to describe the structure of these gripping devices, since they are well known to those skilled in the art, and further because a detailed description thereof is not necessary for an understanding of the present invention. Sufce it to say that when a wire strand is inserted in one of said gripping devices, and the device operatively locked, it will grip the wire and prevent it from slipping back during the application of tension to the wire.

The structure of one form of tunneling shield according to my invention will be seen from FIGS. 14 to 16. The shield 24 has the usual outer shell or skin 47, the hood portion 28 having a sharpened and hardened peripheral front edge 48 suitably adapted for its operative function of penetrating the earth. It will be observed that the lower front portion of the shield also contains a peripheral sharpened edge portion 49, similarly suited for its intended function of penetnating the earth. Although the particular shield illustrated has a semi-cyli-ndrical hood portion, it is understood that this invention is not limited thereto, since full or various forms of partially cylindrical ploughing sections can be employed with my invention with the same force and effect as the particular form illustrated in the drawings. Disposed medially within the shield is said diaphragm member 32 comprising the rear diaphragm portion 56 and the front diaphragm portion 51. In the particular embodiment illustrated, said diaphragm 32 is composed of a plurality of channel-like `sections 53 suitably attached, such as by welding, to the inner circumferential portion of the shell 47, there being one series of such sections forming said rear diaphragm 50, and another forwardly disposed series of sections 54 forming the front diaphragm portion 51. Bridging the circumferential gap between the legs 55 and 56 of said yrespective channel sections 53 and 54 is the annular wall 57-of cylindrical configuration-said wall and the portion of shell 47 disposed over the diaphragm 32, together with the respective rear and front webs 58 and 59 of said channel-like members 53 and 54, forming the hollow interior chamber 60 of said diaphragm member 32. Said annular wall 57 has a plurality of apertures 61 therein over which are disposed a plurality of cover plates 62 suitably attached to wall 57 by fasteners 63, whereby said cover plates can be removed and access gained to the chamber 60 whenever required. The rear webs 58 contain a plurality of holes 64 therein for manual access to the chamber 60; and they also contain a plurality of other holes 65 to receive bolt means for use in a form of my invention to be hereinbelow described. The front Webs 59 also contain a plurality of holes 66 for receiving therethrough portions of the tension wires employed in my invention.

Attached to the inside walls of said front webs 59 are the gnipping devices 67 constituting tension member anchoring means, these being similar to the gripping devices 46 hereinabove described in connection with the carriage )member 25 in the power-supply pit 21. Said gripping devices 67 are so arranged with respect to holes 66 that a wire inserted through any of the latter holes will also enter the adjacent gripping device 67 for operative gripping thereby. Adjacent each of said holes 66 is a rounded rest member 66a with which the wires operatively inserted through holes 66 and gripped by devices 67 will be in resting engagement. In the particular form of this apparatus described stiffening members 68 are disposed between the front diaphragm member 51 and the front of the hood 27, to provide structural strength for the hood during its operative engagement with the earth. The said gripping devices 67 are preferably in circumferentially spaced relation within the shield, the said gripping devices 46 on frame 36 being correspondingly spaced.

In the operative practice of my invention, holes 69 and 70 (see FIG. 5) are drilled into the planking 29 and 29a at the starting and power-supply pits, respectively; and then a pipe member 71-shown ycomposed of coupledtogether sections--is forced through the ground through both of these holes. One method of performing this operation is illustrated in FIG. 5 which shows the carriage member 25 reversed from the posit-ion shown in FIG. 1, the hydraulic jacks 42 having their flanges 43 in abutting engagement with the abutment member 72 at the front end of the power-supply pit 21. A push that hereinabove described, since other known `methods may be employed for this operation. The central planking section 34 (FIG. 2) is then removed from the starting pit `20, and in place thereof a wire guide template 74 is inserted, said template consisting of a solid wall 74a containing a plurality of radial slits 75 extending from a central aperture 76 outwardly predetermined `equal distances. It is preferred that the terminal portions 77 of each of said slits 75, and the correspondingly positioned gripping devices 46 on frame 25 and `67 in the s'hield 24 be at substantially the same horizontal levels. A similar wire guide template 78 is positioned at the rearmost portion of the power-supply pit 21, Aas indicated in FIGS. 6, 7 and 8. The said template also contains a plurality of radial slits 79 extending outwardly from the central apertured portion `80 to the outermost portions 80a, the latter being preferably at the same respective horizontal levels as the correspondingly positioned outermost portions 77 of slits 75 of the guide template 74.

A plurality of pre-stressed `tension wires 81, corresponding `in number to the gripping devices 46 and 67 of said carriage member 25 and shield 24, respectively, are then inserted through the pipe 71, so that the rearmost ends of said wires extend rearwardly into the starting pit and the foremost portions extend into, and beyond, the powersupply pit 21. It is preferred that together with said tension wires 81 a signal wire conductor 82 also be introduced, to enable the operators in the starting and powersupply pits to be in communication with each other or to effectuate starting and stopping signal impulses by means known to those skilled in the art. The pipe 71 is then withdrawn, preferably into the power-.supply pit 21, the couplings being successively removed so that the sections of the pipe may be readily detached and carted away.

The rear end portions 81a of the wire strands are then spread out radially, as shown in FIG. 6, and operatively attached to the gripping devices 67 within the diaphragm member 32 of the shield 24.

By referring to FIG. 7 it will be noted that the carriage member has been returned to the position shown in FIG. 1, the hydraulic jack member 42 being in operative engagement with the abutment members 44, in the manner aforesaid. The front end portions 81b of the tension wires are then operatively attached to the respective gripping members 46. Referring to FIG. 8 it will be seen that said wire sections 81h extend forwardly from the gripping device 46. A pull is then applied to one of the wires, such as wire 81C, in the direction of the arrow A (FIG. 8), by any pulling means known to those skilled in the art, such as by a winch,

motor etc. During the application of the pull, the wire 81C is forced radially outwardlyguided by the correspondingly positioned slits 76 and 79 in the respective wire guide templates 74 and `78cutting through the earth until it is in taut condition as indicated by the dot-dash line 81C. Similar pulls are then applied to each one of the wires within the pit 21 until all the wires are taut and extending linearly through the earth section, as shown in FIG. 11. When this point has been reached, the tunnel-forming operation is ready to begin. The tension wires in this nal `position are substantially parallel to the boring axis, it being understood, however, that, within the intent and purpose of this invention, such wi-res may be somewhat convergent or divergent.

vWhen power is operatively applied to the jack members 42, the pistons 41 thereof will exert a forwardly directed force upon the carriage member 25, since the stationary portions of the jack members 42 are in abutment with the stationary abutment members 44. The -rail-mounted carriage 25 will `then move forwardly; and since the tension wires V81 are tautly connected between carriage 25 andthe shield 24, the shield Will be operatively moved forwardly through the earth 22. When the carriage 25 reaches the most forwardly part of its operative path, the gripping members 46 are operatively released, in known manner, the carriage then being returned to the starting position shown in FIG. 11 and indicated by dot-dash lines in FIG. 12, and the gripping Vmembers 46 again operatively brought into gripping engagement with the respective wires positioned therein when the wires are operatively in taut condition. The power is then again operatively applied to the jacks 42, and the pulling action repeated in the manner aforesaid, thereby -further advancing the shield into the ground. It is understood that the steps of excavating and removing the earth are performed by miners or operators substantially in the manner employed in conventional shieldpushing techniques, except that, as aforesaid, the dirt and `muck can be more readily removed through the shield since `there are no obstructing jacks as are present in conventional push mechanisms. With each forward movement, Aa space is provided-the workers setting up primary liners 83 in such spaces in conventional manner. By referring to FIGS. 14 and 16, it will be seen that the segmented primary liners 83 have been set up and attached to each other by fasteners 84 and 85. The distance B (FIG. 16), formed by the operative forward movement of the shield, is to be iilled in by the liner 83a represented by dot-dash lines. FIG. 12 shows the shield partly through the proposed tunnel, and FIG. 13 shows it almost fully throughthe last primary liners to be erected when the shield is in its nal operative position.

It is apparent from the above description that throughout the tunneling process no pressure or tunneling force has been applied to the `liners 83, as is required by the conventional shield-pushing technique. Hence the liners need have no greater structural strength than required for their normal load-bearing functions-thereby resulting in the attainment of all the objectives and advantages hereinabove set forth.

In the form of my invention shown in FIGS. 17 and 18, the liners 86 are shown attached by the fasteners 86a to the diaphragm 32-said fasteners extending through the said holes 65 .in the rear diaphragm member 50. Hence, when the shield 24 is pulled forwardly by the tension members 81, in the manner aforesaid, the liners 86 are simultaneously pulled forwardly. It is thus possible to `assemble a feasible number of such liners outside of the tunnel, making for a more convenient, safer and more economical process.

In the embodiment of my invention illustrated in FIG. 19, the rst liner 87 is shown attached to the diaphragm 32 of the shield 24. The `other liners 88, with outside diameters equal to that of the outside of shell 47, are connected to the liner 87 and to each other by the respective fasteners 89 and 90. Upon the operative forward pull of the .shield 24, in the manner above described, the liners 88 will be operatively moved forwardly without creating the tail void (such as 91 shown in FIG. 18) which is formed when the liners are set up within the shield as is necessary with conventional push-shield apparatus. Accordingly, the costly operation of lling in the tail void can be obviated by my invention.

In the above description, the invention has been disclosed merely by way of example and in preferred manner; but obviously many variations and modifications may be made therein. It is to be understood, therefore, that the invention is not limited to any form or manner of practicing same, except insofar as such limitations are specified in the appended claims.

Iclaim:

1. In a tunnelling apparatus for forming a tunnel through a section of earth, a tunnelling shield at the rear of said earth-section, said shield having a peripheral portion surrounding a boring axis, a plurality of anchoring means in circumferentially spaced relation within the shield, a plurality of parallel tension members attached t0 said respective anchoring means and extending linearly forwardly in the direction of said boring axis through said earth-section, and pulling means positioned forwardly of said earth-section, said pulling means having a carriage movable in the general direction of the longitudinal extent of said tension members, a frame on said carriage having thereon a plurality of spaced gripping members corresponding in number and spacing to said anchoring means and in operative gripping engagement with said respective tension members.

2. In a tunnelling apparatus, the combination according to claim 1, said pulling means having hydraulic jack means disposed rearwardly of said carriage, stationary abutment means disposed rearwardly of said jack means, said jack means being positioned between and in operative engagement with said abutment means and said frame of said carriage, whereby upon an operative actuation of said jack means said carriage means will be moved forwardly and the said shield correspondingly advanced through the medium of said tension members.

3. In a tunneling apparatus, the combination according to claim 1, said anchoring means being circumferentially spaced adjacent the said peripheral portion of said shield, the said gripping members on said frame corresponding in number and position to said anchoring means, said pulling means having a plurality of hydraulic jacks disposed rearwardly of said carriage and each having a stationary cylinder and a movable piston, stationary abutment means disposed rearwardly of said jacks, said cylinders being in abutting engagement with said abutment means and said piston being in abutting engagement with said frame, whereby upon an operative actuation of said jacks said carriage means will be moved forwardly and the said shield correspondingly advanced through the medium of said tension members.

4. In a tunnelling apparatus, a tunnelling shield having a cylindrical shell surrounding a boring axis, an annular diaphragm member attached to the inner surface of said shell, a plurality of circumferentially spaced gripping elements attached to said diaphragm member, a plurality of substantially parallel tension members attached to said gripping elements and extending forwardly therefrom substantially parallel to said boring axis, and pulling means spaced forwardly from said shield and attached to said tension members at circumferential portions of said pulling means spaced to correspond with said circumferentially spaced gripping elements, whereby the operative action of said pulling means will advance said tension members and said shield.

5. In a tunnelling apparatus, a tunnelling shield having a cylindrical shell surrounding a boring axis, an annular diaphragm member attached to the inner surface of said shell, said diaphragm member having front and rear annular walls in spaced relation and disposed in planes substantially normal to the axis of said shell, a plurality of gripping elements attached in circumferentially spaced relation to one of said annular walls and positioned between both of said annular walls, a plurality of substantially parallel tension members attached to said gripping elements and extending forwardly therefrom substantially parallel to said boring axis, and pulling means spaced forwardly from said shield and attached to said respective tension members at circumferential portions of said pulling means spaced to correspond with said circumferentially spaced gripping elements, whereby the operative action of said pulling means will advance said tension members and said shield.

6. In a tunnelling apparatus, the combination according to claim 5, said gripping elements being attached to said front annular wall, said front annular wall having a plurality of apertured portions in registry with said respective gripping elements, said tension members extending through said respective apertured portions.

7. In a tunnelling apparatus, the combination according to claim 5, said diaphragm member having an inner cylindrical wall attached to said front and rear annular walls, said shell, front and rear annular walls and said cylindrical wall combinatively forming a chamber within said diaphragm member, said gripping elements being disposed within said chamber.

8. In a tunnelling apparatus, the combination according to claim 5, said gripping elements being attached to said front annular wall, said rear annular wall having a plurality of apertured portions therein, and fastener means for said apertured portions, whereby a tunnel liner member may be operatively attached to said diaphragm member.

9. In a tunnelling apparatus, the combination according to claim 5, said gripping elements being attached to said front annular wall, said rear annular wall having a plurality of apertured portions therein, an annular tunnel liner member adjacent said diaphragm member and having a plurality of apertured portions in registry with the said apertured portions of said rear annular wall of the diaphragm member, and fastener means extending through the correspondingly positioned apertured portions of said rear annular wall and said liner member.

10. In a tunnelling apparatus, the combination according to claim 5, said gripping elements being attached to said front annular wall, said rear annular wall having a plurality of apertured portions therein, a front tunnel liner member adjacent said diaphragm member and positioned inside said shell, and having a plurality of apertured portions in registry with the said apertured portions of said rear annular wall of the diaphragm member, fastener means extending through the correspondingly positioned apertured portions of said rear annular wall and said liner member, and a rear annular tunnel liner member attached to said front liner member and positioned outside of said shell, the outside diameter of said rear liner member being equal to the outside diameter of the cylindrical shell of said shield and being disposed rearwardly thereof whereby the outer surfaces of said cylindrical shell and rear liner member are ush.

11. In a tunnelling apparatus for forming a tunnel through a section of earth, a tunnelling shield at the rear of said earth-section, said shield having a peripheral portion surrounding a boring axis, a plurality of anchoring means circumferentially spaced within the shield, a plurality of substantially parallel tension members attached to said anchoring means and extending forwardly in the direction of said boring axis through and in engagement with the mass of said earth-section, pulling means positioned forwardly of said earth-section and having thereon a plurality of circumferential gripping members spaced to correspond with the spacing of said anchoring means and in operative gripping engagement with said respective tenslon members, and a tension member guide template having a plurality of apertures therein comprising a central opening and a plurality of substantially radial slits extending outwardly from said central opening, there being one of said slits for each of said tension members, said tension members extending through said apertures.

12. In a tunnelling apparatus for forming a tunnel through a section of earth, a tunneling shield at the rear of said earth-section, said shield having a peripheral portion surrounding a boring axis, a plurality of anchoring means circumferentially spaced within the shieid, a plurality of substantially parallel tension members attached to said anchoring means and extending forwardly in the direction of said boring axis through and in engagement with the mass of said earth-section, pulling means positioned forwardly of said earth-section and having thereon a plurality of circumferential gripping members spaced to correspond with the spacing of said anchoring means in operative gripping engagement with said respective tension members, a rear tension member guide template positioned forwardly of said tunnelling shield, and a front tension member guide template positioned rearwardly of said pulling means, each `of said guide templates comprising a central opening and a plurality of substantially radial slits extending outwardly from said central opening, there being one of said slits for each of said tension members, said tension members extending through said apertures of both of said templates.

13. In a tunnelling apparatus for forming a tunnel through a section of earth, a tunnelling shield at the rear of said earth-section, said shield having a peripheral portion surrounding a boring axis, pulling means positioned forwardly of said earth-section, and tension means extending through and in engagement with the mass of said earth-section, said tension means comprising a plurality of tension members attached to spaced sections of said peripheral portion of the shield and extending forwardly therefrom in the direction of and substantially parallel to its said boring axis and connected to said pulling means at spaced sections thereof positioned to correspond with said spaced sections of said shield.

14. In a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of substantially parallel tension members through and in engagement with the mass of said section and attaching said substantially parallel tension members to the said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, and applying a forward pull to said tension members until said tension members are substantially parallel with said boring axis, and thereby operatively advancing said tension members and said shield through said earthsection.

15. ln a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of substantially parallel tension members through and in engagement with the mass of said section betwen a region rearwardly of said earth-section and a region forwardly thereof, attaching said substantially parallel tension members within said rearward region to said peripheral portion of said shield at spaced portions thereof, positioning said respective tension members linearly forwardly of said peripheral portion, positioning pulling means forwardly of said earth-section and attaching said parallel tension members Within said forward region to said pulling means at portions thereof corresponding to said spaced portions on said shield, and causing said pulling means to exert a forward pull on said tension members until said tension members are substantially parallel with said boring axis,

thereby operatively advancing said tension members and side shield through said earth-section.

16. In a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of substantially parallel tension members between a region rearwardly of said earth-section and a region forwardly thereof, attaching said tension members within said rearward region to circumferentially spaced sections of said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, positioning pulling means forwardly of said earth-section and attaching said tension members within said forward region to circumferentially spaced portions of said pulling means corresponding to said spaced sections of said shields peripheral portion, and causing said pulling means to exert a pull. in the direction of said boring axis on said tension members until said tension members are substantially parallel with said boring axis thereby operatively advancing said tension members and shield throughsaid earth-section.

17. In a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, boring a hole through said earth-section substantially in line with the axis of said shield, passing a plurality of substantially parallel tension members through said bored hole and attaching rear portions of said tension members to circumferentially spaced sections of said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, applying generally forward pulls in the direction of said boring axis to said tension members until they are taut and substantially parallel with said boring axis and applying an additional forward pull to said tension members, thereby operatively advancing said shield through said earthsection.

1%. In a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, boring a hole through said earth-section substantially in line with the axis of said shield, passing a plurality of substantially parallel tension members through said bored hole and attaching rear portions of said tension members to circumferentially spaced sections of said peripheral portion of said shield, positioning said respective tension members to said tension members until they are substantially horizontal and taut, and applying an additional forward pull to said tension members in the direction of said boring axis thereby operatively advancing said shield through said earth-section.

i9. ln a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of substantially parallel tension members through and in engagement with the mass of said section and attaching said substantially parallel tension means to said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, attaching a cylindrical tunnel liner to said shield, and applying a forward pull to said tension members until they are substantially parallel with said boring axis, and thereby operatively advancing said tension members and said shield and said liner through said earth-section.

2li. in a method of tunnelling through a section of earth with a tunnelling shield having a rear tail thereon having a peripheral portion surrounding a boring axis, the step of positioning said shield rearwardly of said earthsection, passing a plurality of substantially parallel tension members through said section and attaching said substantially parallel tension members to said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, selecting a cylindrical tunnel liner having the same outside diameter as the outside diameter of said shield attaching said liner at the rear edge of said tail and therebehind, whereby the outer surfaces of said liner and tail are flush, and applying a forward pull to said tension members until said tension members are substantially parallel with said boring axis, and thereby operatively advancing said shield and said liner through said earth section.

21. In a method of tunnelling through a section of earth with a tunnelling shield having a rear tail thereon having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of substantially parallel tension members through said section and attaching said Substantially parallel tension members to said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, attaching a cylindrical tunnel liner to said shield within said tail, selecting a second cylindrical tunnel liner having the same outside diameter as the outside diameter of said shield, attaching said second liner at the rear edge of said tail and therebehind, whereby the outer surfaces of said second liner and tail are flush, and applying a forward pull to said tension members until said tension members are substantially parallel with said boring axis, thereby operatively advancing said shield and said liners through said earth-section.

22. In a method of tunnelling through a section of earth with a tunnelling shield having a peripheral portion surrounding a boring axis, the steps of positioning said shield rearwardly of said earth-section, passing a plurality of tension members through and in engagement with the mass of said section, attaching said tension members to said peripheral portion of said shield, positioning said respective tension members linearly forwardly of said peripheral portion, and applying a forward pull in a direction substantially parallel to said boring axis to said tension members until said tension members are substantially parallel with said boring axis, and thereby operatively advancing said tension members and said shield through said earth-section.

References Cited by the Examiner UNITED STATES PATENTS 1,948,733 2/1934 Robertson 61-43 X 2,074,003 3/1937 Templeton et al 61-16 2,134,478 10/1938 Hollingsworth 61-85 2,837,324 6/1958 Aschacker 175-53 2,967,401 1/1961 Washabaugh 61-84 FOREIGN PATENTS 841,600 7/1960 Great Britain. 221,648 12/1962 Netherlands.

JACOB L. NACKENOFF, Primary Examiner.

EARL I. WITMER, CHARLES E. OCONNELL,

Examiners.

R. A. STENZEL, Assistant Examiner. 

1. IN A TUNNELLING APPARATUS FOR FORMING A TUNNEL THROUGH A SECTION OF EARTH, A TUNNELLING SHIELD AT THE REAR OF SAID EARTH-SECTION, SAID SHIELD HAVING A PERIPHERAL PORTION SURROUNDING A BORING AXIS, A PLURALITY OF ANCHORING MEANS IN CIRCUMFERENTIALLY SPACED RELATION WITHIN THE SHIELD, A PLURALITY OF PARALLEL TENSION MEMBERS ATTACHED TO SAID RESPECTIVE ANCHORING MEANS AND EXTENDING LINEARLY FORWARDLY IN THE DIRECTION OF SAID BORING AXIS THROUGH SAID EARTH-SECTION, AND PULLING MEANS POSITIONED FORWARDLY OF SAID EARTH-SECTION, SAID PULLING MEANS HAVING A CARRIAGE MOVABLE IN THE GENERAL DIRECTION OF THE LONGITUDINAL EXTEND OF SAID TENSION MEMBERS, A FRAME ON SAID CARRIAGE HAVING THEREON A PLURALITY OF SPACED GRIPPING MEMBERS CORRESPONDING IN NUMBER AND SPACING TO SAID ANCHORING MEANS AND IN OPERATIVE GRIPPING ENGAGEMENT WITH SAID RESPECTIVE TENSION MEMBERS. 